Interlocking mechanism.



No. 802,865. PATENTED OCT. 24, 1905. F. KEIPER. INTERLOCKING MECHANISM.

PPPPPPPPPPPPPPPPP EB.25,1904.

A TTORNE VJ,

UNITED STATES PATENT OFFICE.

INTERLOCKING MECHANISM.

Specification of Letters Patent.

Patented Oct. 24, 1905.

Application filed February 25,1904. Serial No. 195,264.

To all whom it may concern.-

Be it known that I, FRANK KEIPER, a citi-' zen of the United States,residing at Rochester, in the county of Monroe and State of New York,have invented certain new and useful Improvements in InterlockingMechanisms; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

Reference is had to the accompanying drawings, forming a part of thisspecification, and to the reference-numerals marked thereon.

My present invention relates to an improvement in interlocking mechanismsuch as is described in the pending application of A. J. Gillespie,Serial No. 113,686, and has for its purpose increasingthe accuracy andstrength of the interlocking system described therein.

The invention consists of details by which these improvements areembodied, the patentable features being pointed out in the claims at theend of this specification.

In the drawings, F igurel represents apart of the keyboard of avoting-machine, showing the rear portion of the keys and theinterlocking straps with the wedges connected thereto. Fig. 2 shows across-section of the interlocking channel with the wedges andinterlocking blocks in position. Figs. 3 and 4 are perspective views ofthe interlocking straps and wedges; and Figs. 5 and 6 show the form ofthe interlocking block that is preferably used in connection therewith,which interlocking block constitutes the principal feature of thisinvention.

Similar reference-numerals in the diflerent figures indicate similarparts.

The parts herein described have been illustrated, preferably, inconnection with the parts of voting machines, such as are described inthe Gillespie application above referred to, or in connection with theparts illustrated. for example, in the Gillespie patent No. 647,657,patented April 17, 1900, and may be used in connection with that kind ofa machine, either of the vertical type or of the horizontal type, or anyof the voting-machines patented thereafter, although it is obvious thattheinvention is also adapted to any other form of voting-machine towhich this method of interlocking might be applicable.

In Fig. 1 the parts marked 1 represent the votingkeys. 2 refers to theinterlocking straps, to the end of which are connected the wedges 3 andI, which wedges nest together when in unvoted position, the strapsthereof inclosing an interlocking block between them.

The form of the interlocking block I preferably employ is shown in.Figs. 5 and 6, referred to by the reference-numerals 5 and 6, saidblocks consisting of a thick portion (marked 7) having the interlockingsurfaces, which are comparatively narrow, said portion of the blockbeing stiffened and strengthened by a web, (marked 8,) which extendsupward therefrom. The block may be made in a single piece, as isindicated in Fig. 6, or in a double piece, as is indicated in Fig. 5,the purpose of the block shown in Fig. 5 being to provide room for agrouping-pin to pass between the two halves thereof for the purpose ofholding said block against movement in either direction past thegrouping-pin. The block shown in Fig. 5 may be made all in one piece, inwhich the web or the flange thereof may be made even thinner than whatis indicated therein. The object of the shape of this block may bedescribed as follows: In previous experiments interlocking rollers havebeen used instead of the blocks. The size of said rollers is necessarilylimited to their diameter, and in the effort to get the machine as smallas possible, (which experience has shown to be preferably an inch and aquarter between centers of ofiice-lines,) such rollers in an eight ornine party machine must necessarily have a very small diameter and becorrespondingly weaktoo weak, in fact, to resist the bending strainsthatmay be thrown on them when the whole force or leverage of astraight-ticket key is thrown upon a single key. Consequently flatblocks havingaconsiderable width have been resorted to, such as aredescribed in the Gillespie patent and application above referred to, itbeing necessary to secure this depth or width in the block to resist abending strain that may be thrown upon said block in extreme cases.Increasing the width of said block correspondingly increases the surfacewhich is necessarily exposed to the interlocking strap, and it has beenfound by experiment that the interlocking system works best when thesesurfaces are reduced to the fewest possible number, as is described inmy copending application, and is further improved when the amount ofsurface exposed in each contact is reduced to a minimum. This arisesfrom the fact that two ordinary surfaces of metal will lie closertogether under pressure than they will under gravity. The more true thesurfaces are made of course the more intimate will the contact be undergravity or ordinary pressure and the less they will be moved intointimate contact when extraordinary pressure is applied to secure thisresult. It is obvious that it is easier to get the small ridge (marked9) on the interlocking block true than it is to get the whole surface ofsaid block if it were of the same thickness throughout as it is at itsthickest part or that with the samev degree of irregularity in itssurface it will be more easily brought into intimate contact with itsassociated parts. By this is meant that degree of contact under lightcompression, which must exist, so that any further compression, howeversevere or strong, will not seriously diminish the outside measurement ofa series of pieces in such compression even if the force applied be muchgreater than can be applied by a voter in operating the parts of themachine described in the patents above referred to. It is estimated thatthe maximum force on an interlocking strap that can be exercised by avoter, tending to draw the wedge connected to said strap to votedposition against the resistance of the interlock, is from two hundred tofour hundred pounds, and with such pressure as this applied the partsshould yield as little as possible from their normal condition and bepracticallyincompressible long before the maximum pressure is reached.This resultwill be secured, itis believed. from blocks of theabove-described shape better than will be secured if the blocks are soshaped as to interlock over their whole surface. The thick part of theblock may be rounded, so that its contact with the interlocking wedge orstrap will be reduced to a line.

Having thus fully described my invention, what I claim as new is asfollows:

1. A long flat interlocking block having a thick part containing theinterlocking surface, and a thinner web or flange running longitudinallyof said thick part for the purpose of stiffening the same to resistbending strains.

2. A long flat interlocking block the interlocking part being nearlyrectangular in outline and having interlocking surfaces extending acrosssaid blockand covering a small portion thereof, said block beingprovided with a thinner web or flange extending longitudinally acrossthe thicker part for the purpose of stiffening the same.

3. A long flat interlocking block having interlocking surfacesextendingacross opposite sides thereof, said block being nearlyrectangular in outline, and a thinner web or flange for the purpose ofstiffening the interlocking block, said web being provided with recessedportions for securing said block in its proper position in the channel.

4. In an interlocking mechanism for votingmachines, the combination ofinterlocking straps provided with wedges which nest with each other, andinterlocking blocks, each interlocking block being long and flat andhaving a thick part to contact with said wedges and having a thin partto stiffen the block and located out of contact with said strap, wherebythe contact is made wholly between the block and wedge during theoperation of voting.

5. In an interlocking mechanism, the combination with the interlockingstraps and wedges adapted to nest with each other, of a channel,interlocking blocks sup1')orte .l by said channel, said interlockingblocks having long flat portions substantially rectangular in outline onwhich the interlock takes place, and a thinner stiffening web or flange,said web or flange being slotted for engagement with said channel.

6. In an interlocking mechanism, the combination with straps havingwedges thereon, which wedges are adapted to nest with each other, achannel having oppositely-projecting portions, and interlocking blockssu pported in said channel between said straps and wedges, eachinterlocking block being long and flat and substantially rectangular inoutline and havinga tapered portion to facilitate easy engagement of thewedges therewith and also having a thinner stiffening web or flangeextending longitudinally of said block, said web or flange being slottedfor engagement with the opposite projecting portions of the channel.

7. A flat rectangular interlocking block, having a narrow raisedinterlocking surface extending tranversel y to the movement of theinterlocking wedge.

8. An interlocking device consisting of interlocking blocks and wedgesarranged alternately, said interlocking blocks being rectangular inshape and having their broad sides lying parallel to the path ofmovement of the wedges, said broad surfaces having a narrow raisedinterlocking surface extending transversely to the movement of theinterlocking wedge.

9. A rectangular interlocking block extending transverselybetween twosupporting-channels, raised interlocking surfaces on opposite sides ofsaid block, said raised surface extending between the channels, and anextension of said block made thin to avoid interlocking contact thereon,and made wide to stiffen the block against the bending strains to whichit may be subjected.

10. A thin rectangular interlocking block supported at its ends bychannels, said block having a narrow thick portion, on which thickportion only it interlocks.

11. A thin rectangular block supported at its ends by channels, saidblock having a narrow thick portion, on which thick portion only itinterlocks, the balance of the block strengthening the thick portion ofthe block against bending.

I 12. A thin rectangular interlocking block supported at its ends bychannels, said block having a narrow thick portion, on which thickportion only it interlocks, said blocks being arranged in series withinterlocking straps passed between their broad surfaces.

13. An interlocking block of rectangular outline having a raisedinterlocking surface extending transversely across said block andcovering a narrow strip of its broad surface.

14. An interlocking block having a narrow portion, extendingtransversely to the movement of the interlocking wedge, made thick toconfine the interlocking thereto, a wide FRANK KEIPER.

Witnesses:

Gr. WILLARD RICH, RUSSELL B. GRIFFITH.

